Showing posts with label casting. Show all posts
Showing posts with label casting. Show all posts

Friday, August 31, 2012

Shibuichi: Make it yourself

A few years ago I did a little post about when I made shibuichi for the first time.  My friend Victoria Altepeter taught me how to make it.  I get tons of hits on this post and tons of people are directed to my blog when they do a google keyword search for "shibuichi".  I have google analytics, which is how I know how people find my blog.  Its a cool and creepy thing.
Anyway, I thought since I get so much traffic to my blog from people looking to learn how to make shibuichi, that I should do a more detailed post on the matter.  So, here we go.
How to make your own shibiuichi!
Shibuichi is a Japanese alloy of silver and copper.  It can range anywhere between 5% silver to 50% silver with the rest being copper.  Shibuichi is a beautiful pinkish white metal that can take a wide range of patinas to change to many colors from blues and greens to deep reds and oranges.  It works wonderfully, reticulates to amazing textures, and casts well.  Oh, and because of its high copper content, its cheaper than sterling!  I prefer a 70-80% copper and 20-30% silver alloy.
 
 First you need to decide what precentage you want your alloy to be.  Once you have determined that, cut your scrap metal into small pieces and weigh it out (separately by metal).  Keep in mind that if you are using sterling instead of fine silver you have to account for the fact that sterling already is 7.5% copper.  
Your next step is to decide what kind of ingot you are going to pour (sheet or wire).  Then make sure you carbon coat the ingot so your metal will not stick to it.  Do this by lighting just the gas on your oxy/acetylene torch and running the flame over your ingot mold.  The smoke that comes off the gas only flame is dark dirty and will totally coat your mold in carbon.  
 
 See how black it is?
 
Then its time to preheat your crucible.  Make sure your crucible is large enough to hold the amount of metal you are going to pour.  You should have a crucible designated just for shibuichi (although depending on your alloy, it may be ok to use your sterling crucible).  This is so you do not cross contaminate your metals.  Light your torch and heat up your crucible until it is slightly glowing with heat.  Also make sure to give it a coating of flux (borax).  Make sure you always wear protective eyewear when working with the torch, and other appropriate safety gear.
Now you are ready to start melting metal.  This is where it gets fun!  I always start with my higher melting temperature metal first (so in this case, copper).  Put your CLEAN copper scraps into the crucible and heat with the torch until they are completely molten to a liquid state.  Then add your silver and heat until it is melted.  Add a little more borax and scrape any junk off the surface of your liquid metal.  Make sure to stir with a carbon rod so you know the metal is completely molten.  
When all your metal is liquified, you are ready to pour into your ingot.  This takes coordination and practice.  I am not coordinated and almost always spill some out.  Luckily any spills are recoverable!
Try to pour continuously and quickly.  If you go to slow or have breaks, you may not end up with one solid piece when it cools.  
 
 Wait until the metal is no longer red hot before opening the ingot mold, or taking your metal out (depending on which type of mold you are using).  Then you can open it up, take the metal out, quench in water and then pickle.
After pickling I take my ingot to the belt sander and grind off any sharp edges or flashing.  When rolling your metal down in the rolling mill these sharp edges can cause cracks.  If you do see any cracks when rolling out your metal, make sure to grind them completely away right away, otherwise they will just get bigger and bigger each time you feed your metal through the rolling mill.
   As you can see from the picture below, I poured too slowly and got a separation of the metal in my ingot.  This part needs to be cut off or it will just crack.

 
After grinding and rounding all edges, you are ready to mill your metal down to whatever form you want it in (sheet or wire).  You don't have to anneal yet, because when pouring the ingot the metal definitely reached annealing temperature!  Set your rolling mill for the thickness of your ingot, and then tighten just slightly.  You dont want to force the metal too fast.  Each time you feed your metal through the rollers, you can tighten them down a little.  All mills are different, but I usually tighten between and eighth and a quarter of a turn.  

Once you feel more resistance, its time to anneal.  I usually only roll my ingot through the mill 4-5 times before annealing.  Just keep annealing and running it through the mill until you get the thickness that you want!

 
Viola, you now have your very own hand made shibuichi!  For more direction on making shibuichi, check out this video of my friend, Andy Cooperman.

 And here is a picture of the shibuichi I rolled out and then reticulated.

Now you can see how easy it is to make your own shibuichi.  Have fun!

Sunday, May 2, 2010

Casting with my 3D Class

A couple of weeks ago I did a pewter casting project with my 3D class. As always the project was a hit and all the students had a great time. Who doesn't love playing with fire?! Here are some pics from the casting day:We used ceiling tiles as our molds...just carved into them with exacto blades and dental tools.

Heating the pewter in a cast iron ladle with an acetylene torch.
Waiting until just the right temperature so the metal will freeze up in the mold and not pour straight through. Pewter has a really low melting temperature and stays molten for a long time so this takes a little practice.
Getting ready to pour the metal.
Pouring!
And just a couple of the final products.

Monday, November 24, 2008

Whirlwind Day

Saturday was absolutley crazy. Wonderful, but crazy. I had to be at Mesa Art Center at 8:00 am to set up my booth for the Holiday Art and Music Festival. The fair has been going on for 3 years now, and my friend and studio mate Victoria Altepeter and I have shared a booth together all 3 years. So we got all set up, and then I had to drive all the way to downtown Phoenix to teach my etching class at Phoenix Center for the Arts (more on that later). It was fun, but then after the 3 hour class I had to rush back over to Mesa to watch my booth for the last 2 hours of the show before takedown. We got all cleaned up, I drove home and unloaded the truck really quick and then dashed to the movie theater to go see Twilight. Besides the fact that I got virtually NO sleep for a week before the show because I was frantically trying to get jewelry made, that was a really exhausting day! It was super fun though. Oh, and can I just point out that it was a beautiful, sunny 78 degrees?! I know you are all jealous!!!
My husband sat at the booth with Victoria while I was teaching. I was so happy that he was willing to help me out. I am a lucky girl! I think he may have even had fun:)
Victoria won 1st place jurors award for the show because her jewelry is AMAZING and she gets her booth for free next year! I will be sad that we won't be sharing the booth, but we decided that we will just have to have our booths right next to eachother so we can still be together! This is some of the jewelry (below) she had at the show, isn't it amazing?! She has opened an etsy shop and is working on getting things listed. You should check it out. If she doesn't have much listed, check back later as she is just getting started!
These are her married metal belt buckles. She uses lots of different patinas in her work. Aren't they gorgeous?
These are some of her cast organic brooches.
Sky map rings in brass and sterling silver.
Galaxy brooches.
Anyway, it was really a fun day and we both did really well. There was so much traffic! Our booth was busy all day. One thing that was so great was that we had so many friends come to support us. So many of our customers were return customers from last year, which is such a compliment. We were so glad to have so many friends, family members and supporters come and stop by our booth. Thank you so much. You make all of our hard work worth it!

Sunday, April 6, 2008

Cuttlefish Casting

Last week I taught my 3D Design class how to do cuttlefish casting. I had them carve their own molds and then we cast them in pewter. All but one of them worked out, but it was definetly a trial and error experience. Pewter melts at such a low temperature and stays liquid for so long! If we poured it right when it was molten it would just pour right through the mold. We had to get it molten and then let it cool for like 5 minutes before we poured it. That was the only way it would stay in the mold! Luckily we were able to pour multiple times in order to get a good cast. My students seemed to really enjoy it, mostly because they got to play with fire! I now have a better understanding of why most metalsmiths don't enjoy working in pewter. Enough said.